This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: The primary objective of this study is to determine whether chronic docosahexaenoic acid (DHA) supplementation slows the progression of cognitive and functional decline over 18 months in mild to moderate Alzheimer s disease (AD), as indicated by change in scores on the ADAS-Cog and CDR-SOB. Aims: (1) To determine whether chronic DHA supplementation slows the progression of cognitive and functional decline over 18 months in mild to moderate AD, as indicated by change in scores on ADAS-cog and CDR-SOB;(2) To determine if chronic DHA supplementation exerts anti-amyloid, antioxidant, or neuroprotectant effects, using validated biomarkers of these mechanisms;(3) To determine the effects of chronic DHA supplementation on plasma and urine biomarkers of oxidative damage in AD. The relationship between the biomarker and clinical course will also be determined in order to establish whether these accessible biomarkers have a useful role in clinical trials;(4) To determine the effects of other relevant micronutrients on the clinical course of AD, and on the response of the clinical course to DHA supplementation